Wave-Profile GIS Insulator for Strength and Cleanable Surfaces

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Solution Overview

Problem

Existing insulators for gas-insulated switchgear face challenges in achieving sufficient mechanical performance for high-voltage applications while facilitating easy cleaning, as they often have limited wall thickness and sharp edges that lead to stress concentration and electrical field strength issues, making them prone to failure during servicing.

Innovation Solution

An insulator with a web portion featuring a complex wave structure, where the inner and outer wave profiles have a radius of curvature between 2 mm and 10,000 mm, providing increased mechanical strength and ease of cleaning by avoiding sharp edges and stress concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the wall thickness of the insulator is increased to meet mechanical performance requirements, then the mechanical strength is improved, but the injection molding process becomes more difficult and production complexity increases

Engineering Contradiction:
Improvemechanical strengthVSAvoidinjection molding difficulty
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The insulator employs a triangular wave-like cross-section with curved surfaces instead of sharp edges. This curvature design maintains mechanical strength while avoiding stress concentration points, enabling the insulator to withstand high burst pressures without requiring excessive wall thickness that would complicate injection molding

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of operation

If a triangular wave-like cross section is used to simplify cleaning, then ease of operation is improved, but sharp edges cause stress concentration and electrical field strength issues

Engineering Contradiction:
Improveease of cleaningVSAvoidmechanical performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The triangular wave-like cross-section is modified with curved surfaces throughout, eliminating sharp edges and peaks. This curvature maintains the simplified cleaning advantage of the wave design while preventing stress concentration and high electrical field strength, thereby ensuring mechanical reliability under high burst pressures

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Strength

If the number of waves in the triangular wave-like cross section is increased to improve mechanical performance, then strength is improved, but cleaning difficulty increases due to closer spacing

Engineering Contradiction:
Improvemechanical strengthVSAvoidease of cleaning
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The curved surface design of the triangular wave-like cross-section allows for optimized wave spacing and configuration. The curvature eliminates sharp edges that would create cleaning difficulties, while the overall wave structure provides the necessary mechanical strength. The design balances the number of waves to maintain both structural integrity and cleanability

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Manufacturing precision

If sharp edges are present in the insulator design, then manufacturing precision is improved, but stress concentration occurs under high burst pressure

Engineering Contradiction:
Improveedge sharpnessVSAvoidresistance to burst pressure
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The insulator design replaces all sharp edges with curved surfaces throughout the triangular wave-like cross-section. This curvature eliminates stress concentration points that would occur under high burst pressure, while the overall precise geometric form maintains manufacturing precision. The curved design allows the insulator to distribute stress evenly across its structure

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3888206B1Insulator for a medium- or high-voltage gas-insulated switchgear
Publication Date: 2024.01.03 HITACHI ENERGY SWITZERLAND AG
  • EP3888206B1 patent drawingFigure 1
  • EP3888206B1 patent drawingFigure 2~3
  • EP3888206B1 patent drawingFigure 4A~4C

AI summary

An insulator (100) for a gas-insulated device is provided, comprising an injection-molded insulator disc (101) and a conductor (102), wherein the insulator disc (101) comprises a first circumferential surface (103), a second circumferential surface (104) disposed radially outwards from the first circumferential surface (103), and a web portion (105) connecting the first circumferential surface (103) and the second circumferential surface (104), characterized in that the web portion (105) comprises a wave structure, the web portion (105) having an inner wave profile (106) at the first circumferential surface (103) and an outer wave profile (107) at the second circumferential surface (104), and the inner wave profile (106) and the outer wave profile (107) have a radius of curvature of 2 mm or more and 10,000 mm or less. Further aspects provide a gas-insulated switchgear comprising at least one insulator (100) according to the above, use of the insulator (100) according to the above in a medium-voltage or high-voltage switchgear, and a method for production of the insulator (100) according to the above.